1. Field of the Invention
The present invention relates to a photo-voltaic device and a display apparatus, and more particularly to a photo-voltaic cell device and a display panel.
2. Description of Related Art
In general, a photo-voltaic cell device is often made of silicon or group III-V semiconductors. After the photo-voltaic cell device is irradiated, free electron-hole pairs are generated in a material layer of the photo-voltaic cell device, and charges are separated because of electric field effects, so as to form a semiconductor device having a voltage difference caused by the electric field effects. Operation principles of the photo-voltaic cell device are associated with the semiconductor energy band theory, conduction of carriers in semiconductor materials, P-N (positive-negative type) diode properties, and so on.
FIG. 1 is a schematic structural view of a conventional photo-voltaic cell device. Referring to FIG. 1, the conventional photo-voltaic cell device 100 includes a first electrode 110, a P-type semiconductor layer 120 such as a P-type silicon layer, an N-type semiconductor layer 130 such as an N-type silicon layer, and a second electrode 140. The P-type silicon layer 120 is disposed on the first electrode 110, and the N-type silicon layer 130 is disposed on the P-type silicon layer 120. The second electrode 140 is disposed on the N-type silicon layer 130.
Normally, the P-type silicon layer 120 and the N-type silicon layer 130 are made of a silicon material doped with a dopant, such as an amorphous silicon layer or a doped polysilicon layer. A so-called P/N junction or a depletion region is formed at a junction of the P-type silicon layer 120 and the N-type silicon layer 130. Therefore, when the depletion region or the P-type and N-type silicon layers 120 and 130 are irradiated, the energy from the light results in separation of positive and negative charges in the depletion region; namely, additional free electron-hole pairs are generated. The positive charges h+ (holes) and the negative charges e− (electrons) are seperated and respectively moved towards the positive doped layer (the P-type silicon layer 120) and the negative doped layer (the N-type silicon layer 130) and aggregate. As such, when a load circuit is connected to the first electrode 110 and the second electrode 140, a photo-voltaic current is introduced to drive the load circuit.
Nonetheless, the photo-voltaic cell device mainly made of silicon (e.g. a silicon photo-voltaic cell device or a polysilicon photo-voltaic cell device) has a photo-voltaic conversion efficiency at approximately 15% in average. The silicon photo-voltaic cell device is easily to be decayed by the sunlight or external thermal energy due to silicon recrystalline or rearrangement. As a result, how to develop a novel type of film layer material for improving the photo-voltaic conversion efficiency and lifetime of the photo-voltaic cell device has always attracted people's attention.